Also called: WAC testing, waste soil classification, WM3 assessment, soil sampling

Soil testing and waste classification: WAC tests, costs and when you need them

Before excavated soil leaves site, it has to be classified as hazardous or non-hazardous, and landfills often need a WAC test too. That means sampling and lab analysis. Lab prices for classification with WAC run from about £375 to £550 a sample, depending on turnaround. Find local soil testing.

Who must classify
the waste producer
Soil codes
17 05 04 or 17 05 03*
Classification + WAC
about £375–£550 a sample
Standard lab turnaround
about 5–10 working days
TopsoilMade groundNatural clay Samples to lab 6 ft Trial pit
Samples taken from each soil layer in a trial pit and sent to a lab. Illustrative, not to scale.

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Soil testing for waste means taking samples of the soil you're digging out and having a laboratory analyse them, so the soil can be classified as hazardous or non-hazardous and, if it's going to landfill, checked against the landfill's waste acceptance criteria (WAC). Muck-away firms and landfills often won't take a load without the results.

Why soil has to be tested

  • It's your legal duty. Under the waste duty of care, the business producing the waste must classify it before it's collected, disposed of or recovered.
  • Soil can go either way. Excavated soil has two possible waste codes: 17 05 04 (non-hazardous) and 17 05 03* (hazardous, containing dangerous substances). Which one applies depends on what's in it, so it has to be assessed.
  • Landfills need proof. Before waste goes to landfill it needs a basic characterisation, and landfills for inert or hazardous waste also need leaching test results.
Made ground and brownfield sites

Soil from old industrial land, demolition sites or "made ground" (previously filled or disturbed ground) is the most likely to contain contaminants such as oils, heavy metals or asbestos. Budget for testing early on these jobs.

Classification and WAC: two different tests

Always needed

Waste classification (WM3)

Lab analysis of what's in the soil, assessed against the government's technical guidance (WM3), to decide if it's hazardous or non-hazardous and give it a waste code.

This decides how the waste is handled and where it can go.

For inert and hazardous landfill

WAC testing

A leaching test that shows whether the soil meets a particular landfill's acceptance limits.

WAC results can't be used to classify waste. They're only for landfill acceptance.

Where the soil is goingClassificationWAC leaching test
Inert landfillNeededNeeded
Non-hazardous landfill (non-hazardous soil)NeededNot normally needed, but composition testing is
Stable non-reactive hazardous cellNeededNeeded
Hazardous landfillNeededNeeded

How soil testing works

  1. Plan the samplingA consultant or lab sets a sampling plan. The government guidance says soil classification needs multiple samples, with different layers and areas assessed separately.
  2. Take the samplesFrom trial pits, boreholes or stockpiles, either by a consultant on site or by you with a sampling kit.
  3. Lab analysisA UKAS or MCERTS accredited lab tests for contaminants, often including an asbestos screen.
  4. Assessment and reportThe results are assessed to give each sample a classification and waste code, plus WAC results if asked for.
  5. Share with your muck-away firmThe haulier and landfill use the report to accept the waste and price the load.

What soil testing costs

From published prices. Costs depend on the number of samples, the tests and how quickly you need results.

£375–£550a sample for classification, WAC and an asbestos screen, from 7-day to 3-day turnaround (one lab's published prices, plus VAT)
£250–£400a sample for a full contamination panel
5–10 daysstandard lab turnaround; express 1–3 days, usually at extra cost
  1. Number of samplesMore soil types, layers and areas mean more samples.
  2. Test suiteClassification alone costs less than classification plus WAC and asbestos.
  3. TurnaroundFaster results cost more per sample.
  4. Site visitConsultant sampling is usually charged separately; DIY sampling kits cost less.

If the soil is hazardous

Consignment note Required

Hazardous waste in England moves on a hazardous waste consignment note, kept for 3 years, rather than a standard waste transfer note.

Specialist carrier

Check your muck-away firm can take hazardous soil and knows which sites will accept it.

Higher disposal cost

Hazardous soil goes to fewer, more expensive sites. Test early so it doesn't surprise the budget.

Don't mix it Not allowed

You must not mix hazardous waste with non-hazardous waste unless an environmental permit specifically allows it. Keep contaminated soil apart from clean soil.

See our muck away guide for load sizes, landfill tax and moving the soil once it's classified.

Questions to ask a soil testing company

  • Is your lab UKAS or MCERTS accredited for these tests?
  • How many samples do we need, and who takes them?
  • Does the price include classification, WAC and an asbestos screen?
  • What's the turnaround, and what does express cost?
  • Will the report give a waste code my muck-away firm and landfill will accept?
  • Is the site visit charged separately?

Prices in this guide are typical ranges from suppliers' published price lists and cost guides. They change and vary by area, so always confirm the price with the supplier before you book. Rules, fees and tax rates are checked against official sources.

Soil testing questions

Do I need to test soil before muck away?

Usually, yes. The business producing the waste must classify it before it's collected, and soil can be either hazardous (17 05 03*) or non-hazardous (17 05 04) depending on what's in it, so it normally needs sampling and lab analysis. Landfills for inert or hazardous waste also need WAC leaching test results.

What is a WAC test?

WAC stands for waste acceptance criteria. It's a leaching test that shows whether soil meets a landfill's acceptance limits. It's needed for inert and hazardous landfills, but the government guidance says WAC results must not be used to decide whether waste is hazardous; that needs a separate classification.

How much does soil testing for waste cost?

One lab's published prices for classification, WAC and an asbestos screen run from about £375 a sample for 7-day results to £550 for 3-day results, plus VAT. A full contamination panel is typically £250 to £400 a sample. Consultant site visits are usually extra.

How long does soil testing take?

Standard lab analysis usually takes 5 to 10 working days. Express results in 1 to 3 days are available at extra cost.

How many soil samples do I need?

It depends on the site. The government guidance says soil classification needs multiple samples, with different layers and areas assessed separately. A consultant or lab will set a sampling plan.

What's the difference between WM3 and WAC?

WM3 is the government's technical guidance used to classify waste as hazardous or non-hazardous. WAC testing checks whether waste meets a specific landfill's acceptance limits. Classification is always needed; WAC is needed for inert and hazardous landfills.

What happens if soil is hazardous?

It must move on a hazardous waste consignment note (kept for 3 years in England), with a carrier and disposal site that can accept it, which costs more. You must not mix hazardous waste with non-hazardous waste unless an environmental permit allows it, so keep contaminated soil apart from clean soil.